| Kernel driver asc7621 | 
 | ================== | 
 |  | 
 | Supported chips: | 
 |     Andigilog aSC7621 and aSC7621a | 
 |     Prefix: 'asc7621' | 
 |     Addresses scanned: I2C 0x2c, 0x2d, 0x2e | 
 |     Datasheet: http://www.fairview5.com/linux/asc7621/asc7621.pdf | 
 |  | 
 | Author: | 
 | 		George Joseph | 
 |  | 
 | Description provided by Dave Pivin @ Andigilog: | 
 |  | 
 | Andigilog has both the PECI and pre-PECI versions of the Heceta-6, as | 
 | Intel calls them. Heceta-6e has high frequency PWM and Heceta-6p has | 
 | added PECI and a 4th thermal zone. The Andigilog aSC7611 is the | 
 | Heceta-6e part and aSC7621 is the Heceta-6p part. They are both in | 
 | volume production, shipping to Intel and their subs. | 
 |  | 
 | We have enhanced both parts relative to the governing Intel | 
 | specification. First enhancement is temperature reading resolution. We | 
 | have used registers below 20h for vendor-specific functions in addition | 
 | to those in the Intel-specified vendor range. | 
 |  | 
 | Our conversion process produces a result that is reported as two bytes. | 
 | The fan speed control uses this finer value to produce a "step-less" fan | 
 | PWM output. These two bytes are "read-locked" to guarantee that once a | 
 | high or low byte is read, the other byte is locked-in until after the | 
 | next read of any register. So to get an atomic reading, read high or low | 
 | byte, then the very next read should be the opposite byte. Our data | 
 | sheet says 10-bits of resolution, although you may find the lower bits | 
 | are active, they are not necessarily reliable or useful externally. We | 
 | chose not to mask them. | 
 |  | 
 | We employ significant filtering that is user tunable as described in the | 
 | data sheet. Our temperature reports and fan PWM outputs are very smooth | 
 | when compared to the competition, in addition to the higher resolution | 
 | temperature reports. The smoother PWM output does not require user | 
 | intervention. | 
 |  | 
 | We offer GPIO features on the former VID pins. These are open-drain | 
 | outputs or inputs and may be used as general purpose I/O or as alarm | 
 | outputs that are based on temperature limits. These are in 19h and 1Ah. | 
 |  | 
 | We offer flexible mapping of temperature readings to thermal zones. Any | 
 | temperature may be mapped to any zone, which has a default assignment | 
 | that follows Intel's specs. | 
 |  | 
 | Since there is a fan to zone assignment that allows for the "hotter" of | 
 | a set of zones to control the PWM of an individual fan, but there is no | 
 | indication to the user, we have added an indicator that shows which zone | 
 | is currently controlling the PWM for a given fan. This is in register | 
 | 00h. | 
 |  | 
 | Both remote diode temperature readings may be given an offset value such | 
 | that the reported reading as well as the temperature used to determine | 
 | PWM may be offset for system calibration purposes. | 
 |  | 
 | PECI Extended configuration allows for having more than two domains per | 
 | PECI address and also provides an enabling function for each PECI | 
 | address. One could use our flexible zone assignment to have a zone | 
 | assigned to up to 4 PECI addresses. This is not possible in the default | 
 | Intel configuration. This would be useful in multi-CPU systems with | 
 | individual fans on each that would benefit from individual fan control. | 
 | This is in register 0Eh. | 
 |  | 
 | The tachometer measurement system is flexible and able to adapt to many | 
 | fan types. We can also support pulse-stretched PWM so that 3-wire fans | 
 | may be used. These characteristics are in registers 04h to 07h. | 
 |  | 
 | Finally, we have added a tach disable function that turns off the tach | 
 | measurement system for individual tachs in order to save power. That is | 
 | in register 75h. | 
 |  | 
 | -- | 
 | aSC7621 Product Description | 
 |  | 
 | The aSC7621 has a two wire digital interface compatible with SMBus 2.0. | 
 | Using a 10-bit ADC, the aSC7621 measures the temperature of two remote diode | 
 | connected transistors as well as its own die. Support for Platform | 
 | Environmental Control Interface (PECI) is included. | 
 |  | 
 | Using temperature information from these four zones, an automatic fan speed | 
 | control algorithm is employed to minimize acoustic impact while achieving | 
 | recommended CPU temperature under varying operational loads. | 
 |  | 
 | To set fan speed, the aSC7621 has three independent pulse width modulation | 
 | (PWM) outputs that are controlled by one, or a combination of three, | 
 | temperature zones. Both high- and low-frequency PWM ranges are supported. | 
 |  | 
 | The aSC7621 also includes a digital filter that can be invoked to smooth | 
 | temperature readings for better control of fan speed and minimum acoustic | 
 | impact. | 
 |  | 
 | The aSC7621 has tachometer inputs to measure fan speed on up to four fans. | 
 | Limit and status registers for all measured values are included to alert | 
 | the system host that any measurements are outside of programmed limits | 
 | via status registers. | 
 |  | 
 | System voltages of VCCP, 2.5V, 3.3V, 5.0V, and 12V motherboard power are | 
 | monitored efficiently with internal scaling resistors. | 
 |  | 
 | Features | 
 | - Supports PECI interface and monitors internal and remote thermal diodes | 
 | - 2-wire, SMBus 2.0 compliant, serial interface | 
 | - 10-bit ADC | 
 | - Monitors VCCP, 2.5V, 3.3V, 5.0V, and 12V motherboard/processor supplies | 
 | - Programmable autonomous fan control based on temperature readings | 
 | - Noise filtering of temperature reading for fan speed control | 
 | - 0.25C digital temperature sensor resolution | 
 | - 3 PWM fan speed control outputs for 2-, 3- or 4-wire fans and up to 4 fan | 
 | 	tachometer inputs | 
 | - Enhanced measured temperature to Temperature Zone assignment. | 
 | - Provides high and low PWM frequency ranges | 
 | - 3 GPIO pins for custom use | 
 | - 24-Lead QSOP package | 
 |  | 
 | Configuration Notes | 
 | =================== | 
 |  | 
 | Except where noted below, the sysfs entries created by this driver follow | 
 | the standards defined in "sysfs-interface". | 
 |  | 
 | temp1_source | 
 | 	0 	(default) peci_legacy = 0, Remote 1 Temperature | 
 | 			peci_legacy = 1, PECI Processor Temperature 0 | 
 | 	1 	Remote 1 Temperature | 
 | 	2 	Remote 2 Temperature | 
 | 	3 	Internal Temperature | 
 | 	4 	PECI Processor Temperature 0 | 
 | 	5 	PECI Processor Temperature 1 | 
 | 	6 	PECI Processor Temperature 2 | 
 | 	7  PECI Processor Temperature 3 | 
 |  | 
 | temp2_source | 
 | 	0 	(default) Internal Temperature | 
 | 	1 	Remote 1 Temperature | 
 | 	2 	Remote 2 Temperature | 
 | 	3 	Internal Temperature | 
 | 	4 	PECI Processor Temperature 0 | 
 | 	5 	PECI Processor Temperature 1 | 
 | 	6 	PECI Processor Temperature 2 | 
 | 	7 	PECI Processor Temperature 3 | 
 |  | 
 | temp3_source | 
 | 	0 	(default) Remote 2 Temperature | 
 | 	1 	Remote 1 Temperature | 
 | 	2 	Remote 2 Temperature | 
 | 	3 	Internal Temperature | 
 | 	4 	PECI Processor Temperature 0 | 
 | 	5 	PECI Processor Temperature 1 | 
 | 	6 	PECI Processor Temperature 2 | 
 | 	7 	PECI Processor Temperature 3 | 
 |  | 
 | temp4_source | 
 | 	0 	(default) peci_legacy = 0, PECI Processor Temperature 0 | 
 | 			peci_legacy = 1, Remote 1 Temperature | 
 | 	1 	Remote 1 Temperature | 
 | 	2 	Remote 2 Temperature | 
 | 	3 	Internal Temperature | 
 | 	4 	PECI Processor Temperature 0 | 
 | 	5 	PECI Processor Temperature 1 | 
 | 	6 	PECI Processor Temperature 2 | 
 | 	7 	PECI Processor Temperature 3 | 
 |  | 
 | temp[1-4]_smoothing_enable | 
 | temp[1-4]_smoothing_time | 
 | 	Smooths spikes in temp readings caused by noise. | 
 | 	Valid values in milliseconds are: | 
 | 	35000 | 
 | 	17600 | 
 | 	11800 | 
 | 	 7000 | 
 | 	 4400 | 
 | 	 3000 | 
 | 	 1600 | 
 | 	  800 | 
 |  | 
 | temp[1-4]_crit | 
 | 	When the corresponding zone temperature reaches this value, | 
 | 	ALL pwm outputs will got to 100%. | 
 |  | 
 | temp[5-8]_input | 
 | temp[5-8]_enable | 
 | 	The aSC7621 can also read temperatures provided by the processor | 
 | 	via the PECI bus.  Usually these are "core" temps and are relative | 
 | 	to the point where the automatic thermal control circuit starts | 
 | 	throttling.  This means that these are usually negative numbers. | 
 |  | 
 | pwm[1-3]_enable | 
 | 	0		Fan off. | 
 | 	1		Fan on manual control. | 
 | 	2		Fan on automatic control and will run at the minimum pwm | 
 | 				if the temperature for the zone is below the minimum. | 
 | 	3		Fan on automatic control but will be off if the temperature | 
 | 				for the zone is below the minimum. | 
 | 	4-254	Ignored. | 
 | 	255		Fan on full. | 
 |  | 
 | pwm[1-3]_auto_channels | 
 | 	Bitmap as described in sysctl-interface with the following | 
 | 	exceptions... | 
 | 	Only the following combination of zones (and their corresponding masks) | 
 | 	are valid: | 
 | 	1 | 
 | 	2 | 
 | 	3 | 
 | 	2,3 | 
 | 	1,2,3 | 
 | 	4 | 
 | 	1,2,3,4 | 
 |  | 
 | 	Special values: | 
 | 	0			Disabled. | 
 | 	16		Fan on manual control. | 
 | 	31		Fan on full. | 
 |  | 
 |  | 
 | pwm[1-3]_invert | 
 | 	When set, inverts the meaning of pwm[1-3]. | 
 | 	i.e.  when pwm = 0, the fan will be on full and | 
 | 	when pwm = 255 the fan will be off. | 
 |  | 
 | pwm[1-3]_freq | 
 | 	PWM frequency in Hz | 
 | 	Valid values in Hz are: | 
 |  | 
 | 	10 | 
 | 	15 | 
 | 	23 | 
 | 	30  (default) | 
 | 	38 | 
 | 	47 | 
 | 	62 | 
 | 	94 | 
 | 	23000 | 
 | 	24000 | 
 | 	25000 | 
 | 	26000 | 
 | 	27000 | 
 | 	28000 | 
 | 	29000 | 
 | 	30000 | 
 |  | 
 | 	Setting any other value will be ignored. | 
 |  | 
 | peci_enable | 
 | 	Enables or disables PECI | 
 |  | 
 | peci_avg | 
 | 	Input filter average time. | 
 |  | 
 | 	0 	0 Sec. (no Smoothing) (default) | 
 | 	1 	0.25 Sec. | 
 | 	2 	0.5 Sec. | 
 | 	3 	1.0 Sec. | 
 | 	4 	2.0 Sec. | 
 | 	5 	4.0 Sec. | 
 | 	6 	8.0 Sec. | 
 | 	7 	0.0 Sec. | 
 |  | 
 | peci_legacy | 
 |  | 
 | 	0	Standard Mode (default) | 
 | 		Remote Diode 1 reading is associated with | 
 | 		Temperature Zone 1, PECI is associated with | 
 | 		Zone 4 | 
 |  | 
 | 	1	Legacy Mode | 
 | 		PECI is associated with Temperature Zone 1, | 
 | 		Remote Diode 1 is associated with Zone 4 | 
 |  | 
 | peci_diode | 
 | 	Diode filter | 
 |  | 
 | 	0	0.25 Sec. | 
 | 	1 	1.1 Sec. | 
 | 	2 	2.4 Sec.  (default) | 
 | 	3 	3.4 Sec. | 
 | 	4 	5.0 Sec. | 
 | 	5 	6.8 Sec. | 
 | 	6 	10.2 Sec. | 
 | 	7 	16.4 Sec. | 
 |  | 
 | peci_4domain | 
 | 	Four domain enable | 
 |  | 
 | 	0 	1 or 2 Domains for enabled processors (default) | 
 | 	1 	3 or 4 Domains for enabled processors | 
 |  | 
 | peci_domain | 
 | 	Domain | 
 |  | 
 | 	0 	Processor contains a single domain (0) 	 (default) | 
 | 	1 	Processor contains two domains (0,1) |